The Cortec VpCI-422 Rust Remover removes rust and tarnish from steel, iron, copper and brass without creating waste disposal difficulties in most cases, the company says. VpCI-422 is non-flammable and bio-degradable. This product is easy to use: simply apply by dip, spray or brush, allow to sit for 10 to 15 minutes and rinse with an alkaline wash. VpCI-422 contains 92 percent USDA certified bio-based content.